A long-standing problem associated with baling leafy crops, such as alfalfa hay, in dry climates is that of having sufficient moisture in the crop so as to prevent the leaves from shattering or becoming detached from the crop stems during transfer of the crop from the crop windrow to the baler and then as the crop moves through the baler. Such a crop has a moisture content of between 70-80%, determined on a wet basis, when first cut and windrowed. Traditionally the windrowed crop has been permitted to dry down to a few percentage points above a desired storage moisture content and then to let the bale dry to this desired moisture content. Leaf shatter becomes a serious problem when the moisture content of the leafy crop drops below about 14% prior to baling.
One somewhat successful procedure to re-hydrate crop during the baling process has been to inject steam into the crop during the baling process. U.S. Pat. Nos. 6,109,008 and 5,758,479 disclose equipment for accomplishing this task.
The use of boilers is one of the most common ways of generating steam. A boiler produces steam which is a saturated vapor, which is invisible to the naked eye. Saturated vapor is 100% gaseous water. The problem with using saturated vapor is that, as the saturated vapor is moved from its production source to the points of interaction with the hay, heat or energy is lost from the saturated vapor and condensation occurs resulting in water droplets being formed. When viewing a steam cloud, the water droplets are the visible component.
In prior art systems such as that disclosed in U.S. Pat. No. 5,758,479, for example, heat is first lost into the ambient environment through steam piping extending between a steam generator, located on a towed trailer, and a steam distribution manifold, carried by the baler pick-up. In addition, as the steam travels through the atmosphere from the injection nozzles towards the crop, energy is lost to the atmosphere. In both cases, water droplets are formed as the water changes from the gaseous state to a liquid state and is deposited on the crop. The problem with this is that water droplets are not as rapidly absorbed into the plant material and therefore do not prevent leaf shatter or loss. Furthermore, introduction of water droplets into the crop may cause spoilage, mold growth, and spontaneous combustion.